Drill-chuck.



jaws f and the threads f3 eXtend for less than a quarter of the length of said jaws, and the inner faces of the lower end portions of said jaws are cut away, as shown at f* so that said faces are parallel with the central'axis of the chuck body, and each of said jaws preferably provided with two faces f5 which form a longitudinal gripping bead or edge f whereby said jaws are adapted to grasp andv hold the shank y of adrill or other tool inserted between the same.Y

Fig. 1 of the -f accompanying drawing shows the jaws projected to the fullest extent, and Fig. 2 shows them withdrawn into the body. of the chuck head, while Fig. -l shows said jaws projected suliciently to grasp and hold the shank g of a drill or other tool, in which operation, the said jaws may be projected te any extent between the positions shown in Figs. l and but it will.- be understood, that the drill, or the shank thereof, cannot be passed between the lower ends of the jaws in the position shown .in Fig. l, and in the use of the chuck the jaws j are always projected more or less, the extent of their projection depending` on the transverse dimensions of the shank of the drill to be held thereby.

It will be understood that the jaws f are projected by turning the shell in one direction, and withdrawn into the body oi. the chuck by turning said'shell in the oppt site direction, and in the operation of this device, supposing the parts to be in the position shown in Fig. 2, the shell b is turned slightly in the direction to project the j aws f after which, the shank g ofthe tool is inserted between said jaws, after which said shell is turned so as to further project the jaws and cause them to grasp and hold the tool, and the turning of the chaclr'body by the spindle' or shank h, byfwhich itis oonnected with the machine, increases the pressure of the jaws b on the shank of the tool and causes said jaws to securely grasp and hold the same, and when it is desired, to release the tool, all that is necessary is to stop the machine and turn the shell in the opposite direi-lion, which operation with draws the jaws f and releases the` tool.

ln the construction shown, the threads f of the jaws j' extend for less than a quarter oi' the length of said jaws, and the objecl of this construction is to insure that the threads on said will never extend below the bottom of the conical threaded part c cf" of the central top portion or head c, this result being clearly shown in Fig. 1, in

',said threads, which would result, if said threaded parts of the jaws f extended below the conical threaded part c3, in any position of said jaws.

The formation of the bores e in which the jaws f are longitudinally movable, the slots or grooves e2 and the webs or ribs f on the jaws f prevent the rotation of said jaws in said bores and hold them in operative position at all times, but this result may be accomplished in other ways, and changes in and modifications of theseas well as other features of. the g construction herein shown and described, may be iliade, within the scope of the appended claims, without departing from the spiritA of lmy invention or sacrificing its advantages. j Y

Having' fully described my invention what I claimas new and desire to secure by Letters Patent is A chuck body, comprising an outer rotary shell portion and an inner central top or head portion, said head portion being prof vided with a downwardly extending conically tapered part threaded throughout. its length, and said shell portion being provided with a correspondingly tapered chainber to receive said part, and which is provided with a downward extension which" jaws having a' downward and converging or an upward and divorging movement according to the direction in which Said shell is turned.

ln testimony` that l claim the foregoing as luy invention l have signed my naine in presence of the subscribing witnesses this 28th day of ,lune 1913.

GOR( iE W. EMRICK.

Witnesses c C. MULREAN Y,

S. ANDREWS. 

